The Range Rover MKIII manufactured during the BMW owned model years had the M62 specification engine. The M62 BMW V8 has a severely vulnerable Positive Crankcase Ventilation (PCV) system. The PCV system serves to ventilate the crankcase space inside the engine and return those ventilated gases to the intake manifold for further combustion. The vulnerability in the PCV system centers around the OEM use of rubber hoses that are not oil-resistant. The OEM rubber tubing will quickly become damaged and almost completely blocked with the constant exposure to the oil from the crank case.

The degraded and comprimised rubber hoses can introduce all sorts of strange idle problems and can also in some extreme cases cause severe damage to the engine. A somewhat common possibility exists for sever engine damage in cold weather situations. If water is introduced into the PCV system through degraded hoses, that water can freeze. When that water freezes, the PCV passage way is blocked. The blocked PCV system can cause pressure to build up in the engine crankcase. This situation has been know to blow out engine oil seals and a catastrophic oil leak can ensue. The increased pressure in the PCV system can also simply be due to a colapsed rubber hose. The collapsed rubber hose is much more likely than the freezing situation.

The above scenario has personally happened to myself. Luckily, I caught the oil leak in time and shut the engine down. I have heard other first hand accounts where they were not so lucky and the entire engine has to be rebuilt. So this inspection should be a yearly inspection.

Begin by removing the plastic engine cover

Next, remove the pollen filter try above the engine. This component is very large but comes out in two very simple steps. First remove the rubber weather stripping that extends from the battery compartment all the way across the engine bay to the brake master cylinder. The weather stripping simply pulls gently away and upwards. Then remove the two bolts. The entire plastic pollen filter assembly will slide towards the front bumper.

Now we can better inspect the PCV system. The PCV system is at the rear of the engine. The two primary hoses that we are interested in are displayed below. These two hoses are the most vulnerable and are prone to failure. The hoses should be slightly rigid. If the hoses are mushy in any way, then they should be replaced immediately with oil and fuel resistant hoses. Any stock fuel and oil resistant hose from an auto-parts store will do.

Next we need to inspect the oil separator unit. It is my opinion that the oil separator should be removed once a year and cleaned out. The process is easy and it is a good idea to flush out any residue that has built up. Start by removing the two hose clamps. The you will need to remove the two bolts that are securing the oil separator to the back of the engine.

Rear view of the PCV system. You can see the oil separator attachment points clearly. You can also see additional components that should be inspected for damage. The circular housing in the picture is the one way vent that returns the crankcase gases to the engine intake manifold. This apparatus should be removed and the internal diaphragm inspected if your engine is releasing black smoke at idle or start up.

Next you will need to both inspect and remove the bottom hose fitting on the oil separator. In my case, the bottom hose had completely collapsed and was the cause of my engine seal failure. Remove the clamps and remove the entire oil separator from the engine compartment.

Once the oil separator is removed, it will need to be cleaned with some sort of spirit. You want to flush the unit and remove any debris or accumulated oil. You can see in this picture where I replaced the damaged oil return line.

Some general overview diagrams.

In general, all of the rubber components in this system should be inspected. Hopefully this is a good introduction to the location of the components. Stay on top of the condition of these components it could save your engine one day. I almost lost my engine because I simply did not know how vulnerable the system was to blockage. Imagine losing your engine because of a 2 USD rubber hose. I for one would not be a very happy person.